Marine noise pollution - L20

Whats the difference between noise and sound?

Noise = unwanted sounds that disrupts organisms

Sound: signals we are interested in (what we want to study)

How fast travels sound in water compared to in air?

Sound travels 4,5 times faster in water than in air

Give examples of sources of sounds in the marine, both physical/geological, biological and anthropogenic

Physical/geological (natural sources):

• Waves

• Rain

• Geological activity

Biological sources:

• Fish calls

• Marine mammals

• Birds

Anthropogenic sources:

• Ships

• Sonar

• Construction/pile driving

• Sesmic surveys/air guns

What is noise pollution?

• Noise pollution = harmful/unwanted sound that negatively affects organisms

• Stops quickly when the source is removed

What types of noise are there and whats their impact?

Continuous noise:

• Long duration

• Leads to chronic impact

• Example: shipping traffic

Impulsive noise:

• Short, intensive noise

• Leads to acute impact

• Example: sonar, pile driving

What distinguishes sound pollution from other types of pollution?

• Sound pollution is non-persistent

• Pollution stops when the sound is removed

• Effects may still remain biologically important

Why is sound pollution in the marine important?

For marine organisms sound is essential for:

• Communication

• Navigation

• Predator/prey detection

• Habitat selection

→ Noise disrupts these essential functions

Where does the marine sound pollution come from? How does these sounds affect fish and invertebrates?

Ships and boats:

• Increased stress levels (fish)

• Increased risk of predation (fish)

• Reduced ability to select suitable habitat (fish and coral larvae)

Pile driving:

• Increases metabolic rate in fish and mussels

• Slower growth and worse body conditions (mussels)

Sesmic surveys/air guns:

• Zooplankton: increased mortality

• Scallop larvae: developmental delays and malformations, disrupted reflexes (adults)

• Squid: strandings of giant squid

• Fish: physiological changes, decreased catch rate

Wind farm operations:

• Crabs: disrupted settlement

What kind of effects can noise pollution have in the marine life? What does the effects depend on?

Different kinds of effects:

• Physiological effects

• Behavioral effects

• Ecological/survival effects

Effects depend on:

• Hearing rages

• Sound frequency and intensity

• Life stage

• Type of noice

• Duration of exposure

Give examples of physiological effects of noise pollution in the marine

Physiological effects include both hearing damage and broader stress responses

Physiological effects:

• Auditory effects (hearing damage)

  • Permanent threshold shift (PTS)

  • Temporart threshold shift (TTS)

• Stress responses

• Metabolic changes: ventiliation, heart rate

• Reproduction and developement

• Death

• Injury and developmental abnormalities

• Increased metabolic rate

Give examples of behavioral effects of noise pollution in the marine

Noise changes how animals behave and communicate

Effects:

• Altered movement and feeding

• Disrupted communication

• Changes in signaling/calls

• Avoidance behavior (whales stopping feeding dives during sonar exposure)

How does sound affect reef fish settlement?

Sound enhances reef fish settlement:

Negative effect: for long transport away from the reef the sound from ships can be disrupting, and lead the fish far away from the reefs

Positive effect: shorter transport, that travel close to the reed, can help the fish by leading them to the reef

Give examples of ecological/survival effects of noise pollution in the marine

Noise effects can scale up to affect survival and ecosystems

Effects:

• Increased predator risk (fish respond slower to predator)

• Reduced survival rates

• Disrupted settlement

• Reduced habitat selection ability

What is temporary threshold shift (TTS)?

TTS is a temporary loss of hearing sensitivity after sound exposure. Animals recover hearing over time. TTS can also spread to frequencies above the exposure frequency (higher effect after exposure stoped)

What is permanent threshold shift (PTS)?

PTS is permanent hearing loss caused by intense/prolonged noise exposure. Unlike TTS, recovery does not occur.

What is behavioral response studies (BRS)?

BRS are controlled exposure experiments used to study how animals react behaviorally to sound exposure. Often used with tagged whales and sonar playback experiments.

What is the EU marine strategy framework directive (MSFD)?

• The MSFD is the EU framework for achieving “Good Environmental Status” (GES) in marine waters

• Descriptor 11 regulates underwater noise

• Includes monitoring of continuous and impulsive noise and setting environmental threshold values

How is sound monitored and mitigated (reduced)?

Monitoring:

• EU MSFD:

  • Continuous monitoring of shipping noise and registers for impulsive noise sources

  • Requires member states to define environmental threshold values and assess wheter noise levels harm marine ecosystems

Mitigation examples:

• Shutdown

• Ship speed reduction

• Improved ship/hull/propeller design

• Route management and protected areas

• IMO (international maritime organization) and GloNoise partnership work to reduce noise through international guidelines and management strategies

What ocean sound policies exist in different contries?

EU:

• MSFD regulates underwater noise

• Monitoring and threshold systems exist

USA:

• NMFS (National Marine Fisheries Service) regulates major noise-producing activities such as industry, airguns, pile driving, drilling and construction

Norway:

• Essentially no formal ocean-noise regulation system

• No formal measurement or assessment requirements

Global efforts:

• IMO/GloNoise shipping-noise mitigation initiatives

What global efforts has been done to reduce marine noise pollution?

Global efforts to reduce marine noise pollution are still limited, but some important international initiatives exist:

• IMO (International Maritime Organization) developed international guidelines to reduce underwater noise from shipping.

• GloNoise partnership (IMO, UNDP, GEF) works globally to monitor and reduce shipping noise.

• Particularly Sensitive Sea Areas (PSSAs) use shipping-route management to protect vulnerable ecosystems.

• EU MSFD introduced monitoring systems and some of the first quantitative underwater noise limits.